1. Field of the Invention
The present invention is directed to a radiation gating device, of the type suitable for use in an x-ray diagnostics installation.
2. Description of the Prior Art
German OS 1 441 312 discloses a gating device for an X-ray diagnostics installation which has two diaphragm plate pairs that are arranged offset by 90.degree. relative to one another in parallel planes. The diaphragm plate pairs can be adjusted in opposite directions via their mounts, which are attached at the end-faces of the diaphragm plates.
The Siemens book "Bildgebende Systeme fuer die medizinische Diagnostik", edited by Erich Krestel, published by Siemens A. G., Berlin and Munich, 1980, pages 334 and 335, FIGS. 8.49 and 8.50 shows the beam path of a radiation apparatus in the form of a computer tomograph. The beam of the X-ray radiator is thereby gated to form a fan beam by a focus-proximate gating device and a gating device arranged in front of the arcuate radiation receiver composed of individual detectors. To that end, diaphragm plates arranged lying opposite one another form a slot-shaped opening that is variable via adjustment means. The adjustment of the diaphragm plate ensues in a direction perpendicular to its longitudinal axis, for which appropriate mounts and guides are provided. These mounts and guides are arranged at the end faces of the diaphragm plate aligned perpendicularly relative to the longitudinal axis of the diaphragm plate, so that a large structural width of the gating device is achieved. In order to accomplish the adjustment of the diaphragm plates, the adjustment means must be attached in the adjustment direction of the diaphragm plate, which results in a large structural width of the gating device and a mechanically complicated structure.